In this paper, we report the experimental results on the synthesis of low-density tetraethoxysilane (TEOS)-based silica aerogels prepared under ambient pressure. The drying control chemical additive N, N-Dimethylformamide (DMF) was introduced to the experiments. Before dring, the water within alcogel was exchanged with ethanol and n-hexane. Trimethylchlorosilane (TMCS) was used to modify the hydrophilic gel surface to make sure the final aerogel is hydrophobic. The effects of solvent EtOH and DMF on the properties of the resulting aerogels were investigated. The microstructure, morphology and other properties of the aerogels were studied by FT-IR, TEM and BET measurement. The resulting aerogels have a well-developed mesoporous structure (mean pore size of ~15 nm) with low density (0.08g/cm3), a high specific surface area (1267m2/g) super hydrophobicity (Ө=165o) and high transmissivity (~90%).
Fluorescence enhancement in rare earth doped sol-gel glass by N,N dimethylformamide as a drying control chemical additive